Saturday, February 15, 2020

[Botany • 2020] Ceropegia phuchongensis (Apocynaceae: Asclepiodoideae) • A New Species from eastern Thailand

Ceropegia phuchongensis Kidyoo & K. Suwann.

in Kidyoo & Suwannakote, 2020. 

A new species from Phu Chong-Na Yoi National Park, Ubon Ratchathani Province, eastern Thailand, Ceropegia phuchongensis Kidyoo & K. Suwann. (Apocynaceae, Asclepiadoideae), is described, illustrated and compared with the related C. tenuicaulis Kidyoo. The new species differs in corolla tube shape, color and trichomes inside the corolla tube, as well as pollinium and corpusculum shape. In addition, the gynostegium surfaces of the two species also support the distinctiveness of the new species.

Keyword: Apocynaceae, Asclepiadoideae, Ceropegieae, dry deciduous forest, grass-like habit, Thailand, Tiloris

Fig 3. Illustrations of Ceropegia phuchongensis sp. nov. A. Flowering branch; B. Flower; C. Flower bud; D. Longitudinal section of flower showing corona and gynostegium; E. Top view of gynostegium; F. Calyx; G. Pollinarium; H. Fruit; I. Seed. Drawn by Manit Kidyoo from M. Kidyoo 1570(A-F) and M. Kidyoo 1652(G-I).

Fig 4. Ceropegia phuchongensis sp. nov. A. Habitat; B. Habit; C. Flowers. All photographs by M. Kidyoo.

Fig 1. Reproductive structures of Ceropegia phuchongensis sp. nov. (A-C) and C. tenuicaulis (D-F):
A, D. Flowers; B, E. Longitudinal sections of corolla tubes; C, F. Pollinaria. Photographs by M. Kidyoo.

Fig 2. SEM photographs of gynostegium and corona of Ceropegia phuchongensis sp. nov. (A-C) and C. tenuicaulis (D-F).
A, D. Top view of gynostegia; B, E. Side view of gynostegia (stipes were removed); C, F. Basal parts of staminal corona lobes.

Ceropegia phuchongensis Kidyoo & K. Suwann., sp. nov. 

Diagnosis: Ceropegia phuchongensis differs from C. tenuicaulis in having an ovoid to globose corolla tube of 0.7–1.0 cm length and 0.6–0.9 diam. which is inflated at its mid-length. The interior of this inflated part is yellowish white with irregular purplish brown dots and stripes, and densely covered with wrinkled, whitish trichomes of 0.9– 1.5 mm length. In contrast, C. tenuicaulis has an ovoidtubular corolla tube of 1.7–2.2 cm length and 0.5–0.6 cm diam. The tube has a slightly inflated basal portion and a long narrow upper part. The interior of its inflated part is plain purplish brown and covered with scattered white trichomes of 0.7–1.4 mm length.

Etymology: Ceropegia phuchongensis is named after the Phu Chong-Na Yoi National Park, the type locality.

 Distribution and habitat: Ceropegia phuchongensis is currently known from only two localities in eastern Thailand. This plant is a perennial herb growing in sandy soil among tall grasses in the open area of dry deciduous dipterocarp

Manit Kidyoo and Kamonchanok Suwannakote. 2020. Ceropegia phuchongensis (Apocynaceae, Asclepiadoideae), A New Species from eastern Thailand. Taiwania. 65(2); 101-108.